This invention relates to a novel assembly suitable for reading data based on thermal coupling between the assembly and a storage media.
Techniques capable of reading information on a storage media are known. For example, in optical storage technology, a bit pattern may be realized by crystalline (high conductivity and reflectivity) and amorphous (low conductivity and reflectivity) regions on a phase-change media, wherein bit pattern data may be read back by monitoring a change in reflectance of a focused laser beam.
Our work includes a critique and an evaluation of the capabilities of important and representative reading methods of the type represented by the optical storage technology.
To this end, we first note that an important motivation for efforts in this field is to provide insight and capability so that reading of bit pattern data may be realized at ever-increasing high densitiesxe2x80x94for example, reading at densities larger than 1 Gbit/in2. However, we note that for the case of the representative optical storage technology, the resolution of a focused laser beam is restricted by its wavelength to ≈xcex/2 (xcex is the wavelength of the laser), so that the potential data densities of such devices are accordingly severely limited.
The present invention discloses a novel reading assembly capable of reading information on a storage media at high speed and at a resolution which can qualitatively and profoundly transcend the delimitation of the focused laser beam ≈xcex/2 constraint. For example, the novel assembly of the present invention can provide a capability for reading information on a storage media, e.g., a phase-change media, at high speed (e.g., greater than 0.01 MHz, illustratively 100 MHz) and, at a resolution such that there are storage densities larger than 1 Gbit/in2.
The novel assembly of the present invention can realize these important advantages by controlling and monitoring changes of thermal coupling between the reading assembly and the media, preferably as a near-field thermal coupling. In particular, bit pattern data may comprise a first region which can couple thermally strongly with a reading head (i.e., low thermal resistance between media and reader), and, a second region which can couple only weakly with the reading head (i.e., high thermal resistance between media and reader). The novel assembly includes a structure for sensitively monitoring changes of thermal coupling induced between the assembly and such a media, thereby realizing a reader capability.
Accordingly, we now disclose in a first aspect of the present invention, a novel reading assembly, the assembly comprising:
1) a head-like structure;
2) a temperature sensor supported by the head-like structure, the temperature sensor capable of monitoring thermal coupling between the sensor and a media;
3) a heater element for heating the temperature sensor; and
4) a controller for coordinating a mutual positioning of the head-like structure and a media.
In a second aspect of the present invention, we disclose a novel reading assembly comprising:
1) a head-like structure;
2) a temperature sensor supported by the head-like structure;
3) a temperature transducer supported by the head-like structure and comprising input to the temperature sensor; and
4) a controller for coordinating a mutual positioning of the head-like structure and a media;
the assembly providing a reading capability as the temperature transducer induces a temperature differential between the media and the temperature sensor, thereby developing an information reading signal.
The second aspect of the present invention makes explicit that what is required to develop an appropriate information reading signal may be manifest by providing a temperature differential between the media and the temperature sensor. In particular, the temperature differential may be developed by inter alia heating the media by way of the temperature transducer and abstracting the information signal by a cooler temperature sensor, or, secondly, cooling the media by way of the temperature transducer and abstracting the information signal by a relatively hotter temperature sensor.